I am having a nightmare with my elbow. I am following along with the Rigging Pro tutorial. When I get to the Arm FK/IK stage all is looking good, everything in the right place, but then I position constrain the lower arm IK effector to the hand controller and move the hand controller. Then, after the hand controller is control Z-d into it's original position, the elbow bones are out of place.

Summary: When I set neutral rotation at the proper location, they don't zero out. They stay at 5, 5 in the y and z axis. When I zero this out, it returns to position 2, much to my chagrin. I'm trying to get it zerod on the elbow. Any help is appreciated.
http://www.harveytrade.com/before.jpg
before: position 1
http://www.harveytrade.com/after.jpg
after: position 2
Things I've tried to fix the problem: Set neutral pose just pops it to the second position discussed above (the same one after I moved the hand controller).

Remaking the arm gave me the exact same results so I'm fairly certain I didn't just miss something twice.

Here's what changes: the neutral pose rotation changes from 0 to 5s in two axis. I don't know how to reset this since freezing and "use current pose" under local transforms ppg just moves it to the second position.

I'm confused and out of ideas, if you guys could help me out by giving me something else to try I'd be appreciative. Thanks in advance.

edit: both remove and set neutral pose returns the bones to position 2.

Noratio

06-06-2006, 04:47 PM

I believe it is lowerarm_IK_R z rotation you are having problems with. Try to play with Preferred Rotation Angle on ppg. I've got no Idea why you are having this. I didn't use the supplied mesh doing it and my character had fair rotation modelled to every natural rotation angle. Modelling elbow higher than shoulder in Y-axis will case this kind of behavior while rigging, fixes like above.

Attean

06-06-2006, 05:47 PM

That is it, thank you thank you thank you. I'll remodel and rerig the arm tonight, thanks again!

I had a similar problem but it was with pole vectors in Maya on this same character. Should've been a dead give away but I wasn't thinking outside the box.

Attean

06-10-2006, 08:55 AM

!!!

I rebuilt the arm for a third time and it still does it, even now that the shoulder is DEFINATELY above the elbow and the arm has a nice slanted down-turn, like the reference model. Anyone have any idea?

edit: nevermind, I'm just going to jerry rig it to the new position and stop being stubborn. Would've liked to of figured it out but it aint happening.

Noratio

06-10-2006, 10:18 AM

Hey thats depressing. Is your lowerarm (forearm) still bent only 0.182 degrees forward, that is very little.

Attean

06-11-2006, 03:01 AM

yeah it is. I ended up just moving everything else to it and it worked fine. Was still one of those niggling problems you don't like to succumb to. :)

Sbowling

06-11-2006, 04:36 AM

There are a couple of things that I know of that can sometimes cause problems like this. One would be mirroring an arm (or whatever) after wiring all the parameters. Another I;ve seen is mirroring a bone chain after setting neutral rotation/pose.

I just ran into a problem that drove me crazy for about two hours today where my foot bone would twist when my character was animated, but when I would check all my foot poses from the neutral positon, the problem wouldn't show up. I finally figured out that I had parented some bones to my hip controller and that when I would rotate the hip controller it would cause the foor bones to twist. The problem was really simple to fix by using position constrain, instead of parenting. The biggest problem was just figureing out where the problem was coming from. So, maybe you are looking in the wrong place for the cause of the problem. Load the completed character that comes with the videos and compare what is visible directly under the model.

Noratio

06-14-2006, 10:44 PM

I'm on vids again. Lowerarm twistbone seems to follow upperarm twistbone instead of skinbone 5. Since it should be parented to it your elbow can't be right. Look the vids again and check parenting.

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